U.S. Pat. No. 4,422,919, FABIAN et al. and corresponding German Patent 31 38 438 disclose a compact, direct through-flow cell with an easily exchangeable electrode stack, in which the cell can be adapted to the needs of the particular user by varying such parameters as the salt concentration, throughput, and so forth; by means of a low salt concentration and a high throughput, for instance, a high salt yield can be attained; alternatively, a high current yield can be achieved by means of a high salt concentration and a low throughput.
In such an arrangement, it was shown to be problematic that the flow speed of the liquid flow must be slower than the speed with which the gas bubbles contained in the solution rise, in order to assure complete degassing. The gas bubbles are guided along the elongated, cartridge-like electrode surfaces, so that the electrolyte required for the electrochemical reaction is partly forced away from the active electrode surface. Moreover, sealing provisions are necessary in the region of the electrode stack, to prevent the solution, which is under pressure, from escaping.